1. Field of the Invention
This invention relates to gas turbine combustors and more specifically to an improved cooling scheme for a crossfire tube assembly, which interconnects adjacent can-annular combustors.
2. Description of Related Art
A combustion system for a gas turbine engine, especially those used to generate electricity, are comprised of a number of cylindrical combustors disposed in an annular array about the turbine, commonly referred to as a can-annular combustor. It is a common practice to join these individual combustors by a conduit referred to as a crossfire tube assembly, comprised of a plurality of tubes, to aid in cross ignition between combustors. In operation a combustor with an ignition source, typically a spark plug, ignites the fuel/air mixture and the sudden increase in pressure causes the reaction to pass through the crossfire tube assembly into the adjacent combustor, there by igniting the fuel/air mixture in the adjacent combustor. This process eliminates the need for ignition sources in each combustor.
The crossfire tube assembly engages the adjacent combustors and is held in place at each end by a fastening means such as a retaining clip. Each of the tubes, which together in a typical crossfire tube assembly, mate to each other at their respective free ends to allow combustion gases to pass between adjacent combustors. This intersection is typically a telescoping arrangement and due to assembly tolerances and operating issues this intersection is not adequately cooled and becomes the point of maximum operating temperature. The high temperatures cause premature deterioration of the tubes and in some cases burning of the free ends of the crossfire tubes within the assembly. Premature deterioration and burning of the crossfire tubes can cause damage to the surrounding combustion hardware as well.
It is an object of the present invention to provide a crossfire tube assembly for connecting adjacent combustors in a gas turbine engine.
It is yet another object of the present invention to provide a crossfire tube assembly having an improved cooling configuration to reduce component deterioration due to long-term exposure to elevated temperatures.
In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.